CN113200145B - Portable micro coaxial double-propeller unmanned aerial vehicle and control method thereof - Google Patents
Portable micro coaxial double-propeller unmanned aerial vehicle and control method thereof Download PDFInfo
- Publication number
- CN113200145B CN113200145B CN202110754731.5A CN202110754731A CN113200145B CN 113200145 B CN113200145 B CN 113200145B CN 202110754731 A CN202110754731 A CN 202110754731A CN 113200145 B CN113200145 B CN 113200145B
- Authority
- CN
- China
- Prior art keywords
- unmanned aerial
- aerial vehicle
- air control
- control surface
- propeller
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Images
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B64—AIRCRAFT; AVIATION; COSMONAUTICS
- B64C—AEROPLANES; HELICOPTERS
- B64C27/00—Rotorcraft; Rotors peculiar thereto
- B64C27/04—Helicopters
- B64C27/08—Helicopters with two or more rotors
- B64C27/10—Helicopters with two or more rotors arranged coaxially
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B64—AIRCRAFT; AVIATION; COSMONAUTICS
- B64C—AEROPLANES; HELICOPTERS
- B64C13/00—Control systems or transmitting systems for actuating flying-control surfaces, lift-increasing flaps, air brakes, or spoilers
- B64C13/02—Initiating means
- B64C13/16—Initiating means actuated automatically, e.g. responsive to gust detectors
- B64C13/18—Initiating means actuated automatically, e.g. responsive to gust detectors using automatic pilot
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B64—AIRCRAFT; AVIATION; COSMONAUTICS
- B64U—UNMANNED AERIAL VEHICLES [UAV]; EQUIPMENT THEREFOR
- B64U10/00—Type of UAV
- B64U10/10—Rotorcrafts
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B64—AIRCRAFT; AVIATION; COSMONAUTICS
- B64U—UNMANNED AERIAL VEHICLES [UAV]; EQUIPMENT THEREFOR
- B64U30/00—Means for producing lift; Empennages; Arrangements thereof
- B64U30/20—Rotors; Rotor supports
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B64—AIRCRAFT; AVIATION; COSMONAUTICS
- B64U—UNMANNED AERIAL VEHICLES [UAV]; EQUIPMENT THEREFOR
- B64U50/00—Propulsion; Power supply
- B64U50/10—Propulsion
- B64U50/19—Propulsion using electrically powered motors
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B64—AIRCRAFT; AVIATION; COSMONAUTICS
- B64U—UNMANNED AERIAL VEHICLES [UAV]; EQUIPMENT THEREFOR
- B64U2101/00—UAVs specially adapted for particular uses or applications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B64—AIRCRAFT; AVIATION; COSMONAUTICS
- B64U—UNMANNED AERIAL VEHICLES [UAV]; EQUIPMENT THEREFOR
- B64U2201/00—UAVs characterised by their flight controls
- B64U2201/10—UAVs characterised by their flight controls autonomous, i.e. by navigating independently from ground or air stations, e.g. by using inertial navigation systems [INS]
Landscapes
- Engineering & Computer Science (AREA)
- Aviation & Aerospace Engineering (AREA)
- Mechanical Engineering (AREA)
- Chemical & Material Sciences (AREA)
- Combustion & Propulsion (AREA)
- Remote Sensing (AREA)
- Automation & Control Theory (AREA)
- Control Of Position, Course, Altitude, Or Attitude Of Moving Bodies (AREA)
- Toys (AREA)
Abstract
The invention discloses a portable micro coaxial double-propeller unmanned aerial vehicle and a control method thereof. Coaxial double screw is installed in the transfer line upper end, and four rudders personally submit the cross and distribute in shell bottom outer wall. The automatic pilot system automatically realizes the attitude control of the unmanned aerial vehicle, the unmanned aerial vehicle can generate torque difference by adjusting the rotating speed difference of double propellers and the deflection angle of an air control surface, and the unmanned aerial vehicle can generate pitch angle/roll angle deflection under the action of the control surface, so that the front and back left and right movement is realized. In addition, a circular protective cover can be designed and installed on the periphery of the four control surfaces, so that the control surfaces can be protected, and the effect of utilizing the washing flow of the propeller at the maximum efficiency can be achieved. The unmanned aerial vehicle has the advantages of lightness, smallness, portability, easiness in operation, simplicity in control design, good stability, strong wind resistance, low requirements on application scenes and take-off and landing conditions, flexibility and the like.
Description
Technical Field
The invention relates to the technical field of unmanned aerial vehicles, in particular to a portable microminiature coaxial double-propeller unmanned aerial vehicle and a control method thereof.
Background
With the development of information technology, in the modern war, the unmanned aerial vehicle which is simple to operate, convenient to carry and powerful in function is highly valued by various countries; aiming at the special requirements of individual combat, an aircraft which is convenient to carry and strong in performance is developed. Because the cylindric unmanned aerial vehicle of single rotor has the self problem of spin of organism at present, in order to overcome spin moment of torsion problem, single rotor unmanned aerial vehicle must use the air control surface of very large tracts of land just can overcome the moment of torsion of self, leads to unmanned aerial vehicle itself bulky, and mobility is poor, can't satisfy the demand of high maneuver battle.
Disclosure of Invention
The purpose of the invention is as follows: the invention aims to provide a portable microminiature coaxial double-propeller unmanned aerial vehicle and a control method thereof.
The technical scheme is as follows: in order to realize the purpose of the invention, the adopted technical solution is as follows:
a portable micro coaxial double-propeller unmanned aerial vehicle comprises a cylindrical unmanned aerial vehicle shell, wherein a transmission rod and coaxial double propellers are arranged at the top of the shell, and a coaxial counter-rotating motor, a battery, an autopilot system and four steering engines are arranged in the shell; the double propellers are arranged at the top end of the unmanned aerial vehicle and connected with the output shaft of the counter-rotating shaft motor through a transmission rod; four air control surfaces which are distributed in a cross shape are arranged on the periphery of the bottom end of the shell and are respectively controlled by corresponding steering engines, a first pair of air control surfaces comprises a first air control surface and a second air control surface and are symmetrically arranged on two opposite sides of the outer wall of the shell of the unmanned aerial vehicle, and a second pair of air control surfaces comprises a third air control surface and a fourth air control surface and are symmetrically arranged on the other two sides of the outer wall of the shell of the unmanned aerial vehicle; the autopilot system is used for achieving unmanned aerial vehicle attitude control, and enables the unmanned aerial vehicle to generate torque difference by adjusting double propeller rotation speed difference, so that course deflection motion is achieved, the unmanned aerial vehicle generates pitch angle deflection under the action of a control plane by adjusting deflection angles of a first pair of air control planes, so that front and back motion is achieved, the unmanned aerial vehicle generates roll angle deflection under the action of the control plane by adjusting deflection angles of a second pair of air control planes, and accordingly steering motion is achieved.
Preferably, the coaxial double propellers have opposite rotating directions, and the upper propeller is fixed on the lower motor output shaft of the coaxial counter-rotating motor and rotates anticlockwise; the lower propeller is fixed on an upper motor output shaft of the coaxial counter-rotating motor and rotates clockwise; the output shaft of the coaxial counter-rotating motor forms a transmission rod.
Preferably, the lifting force provided by the coaxial double propellers points upwards along the symmetrical axis of the unmanned aerial vehicle body, the directions of the provided torques rotating along the symmetrical axis of the unmanned aerial vehicle body are opposite, and when the torques formed by the two paddles are the same, the self-rotation of the unmanned aerial vehicle body can be overcome; when the torque formed by the two blades is different, the course deflection action of the unmanned aerial vehicle is realized by utilizing the torque difference; when the clockwise torque acting on the machine body is larger than the anticlockwise torque, the machine body yaw rotates clockwise; when the anticlockwise torque is larger than the clockwise torque, the machine body rotates anticlockwise in a yawing mode.
Preferably, a first fixing plate, a second fixing plate and a third fixing plate are mounted inside the unmanned aerial vehicle shell and are respectively used for fixing the motor, the automatic pilot system, the battery and the steering engine; the first fixing plate, the second fixing plate and the third fixing plate are provided with threading holes and ventilation holes.
Preferably, the middle parts of the four air control surfaces are all designed into hollow cylinders.
Preferably, the lift force that coaxial twin screw provided acts on unmanned aerial vehicle focus top, and the control force that the air rudder face provided acts on below the focus.
Preferably, a circular protective cover is arranged on the periphery of the four air control surfaces.
Preferably, all modules in the unmanned aerial vehicle cabin body are uniformly and reasonably arranged, so that the center of gravity of the unmanned aerial vehicle is on the symmetrical axis of the unmanned aerial vehicle.
Preferably, under a coordinate system of the unmanned aerial vehicle, resultant force borne by the unmanned aerial vehicle comprises propeller pulling force, control surface control force and gravity; the tension vectors generated by the upper propeller and the lower propeller are as follows:
wherein
In order to generate the pulling force for the propeller,
sequentially representing an upper propeller and a lower propeller, wherein the pulling force provided by the propellers is a function of the square of the rotating speed of the motor; the control forces generated by the four control surfaces are as follows:
wherein
，
，
In order to be the density of the air,
for the speed of the propeller air wash acting on the control surface,
is a dimensionless aerodynamic derivative of the control surface,
is the deflection angle of the first air control surface and the second air control surface,
the deflection angles of the third air control surface and the fourth air control surface,
the area of a control surface in the washing flow of the propeller;
the resultant moment borne by the unmanned aerial vehicle comprises torque generated by an upper propeller and a lower propeller and aerodynamic moment generated by the wake flow of the propellers on a control surface; the torque generated by the upper propeller and the lower propeller is as follows:
wherein
The torque generated by the propellers is a function of the square of the rotating speed of the motor; the aerodynamic moment generated by the propeller wake flow on the control surface is as follows:
wherein
，
，
And
for the corresponding dimensionless aerodynamic coefficients,
the length of the force arm from the third air control surface and the fourth air control surface to the axis of the unmanned aerial vehicle,
the length of the force arm from the first air control surface and the second air control surface to the axis of the unmanned aerial vehicle.
The control method of the portable microminiature coaxial double-oar unmanned aerial vehicle comprises the following steps:
when the PID pitch controller obtains a reference pitch angle from the IMU, calculating a reference deflection angle of a first pair of air control surfaces according to the following formula; the PWM signal resolving module calculates a PWM value corresponding to the reference deflection angle of the control surface, then outputs PWM signals to the steering engine of the first pair of air control surfaces to complete deflection of the first pair of air control surfaces, and the unmanned aerial vehicle generates pitch angle deflection under the action of the control surfaces to realize front and back movement;
wherein
Is resultant moment
Three components in the coordinate system of the machine body,
for the three components of the angular velocity vector in the body coordinate system, the points on the variable represent the derivatives,
in order to be the pitch angle,
in order to form a transverse rolling angle,
in order to determine the yaw angle,
is the rotational inertia of the unmanned plane
The respective components of (a); under the coordinate system of the unmanned aerial vehicle, the origin of coordinates is located at the center of mass of the unmanned aerial vehicle,Xthe axis is vertical to the longitudinal axis of the unmanned aerial vehicle and points to the front of the unmanned aerial vehicle,Ythe shaft is perpendicular to the longitudinal axis of the unmanned aerial vehicle and points to the right side of the unmanned aerial vehicle,Zthe shaft points downwards along the longitudinal axis of the machine body;
for the torque generated by the upper and lower propellers,
the moment generated for the first and the second air control surfaces,
the moment generated for the third air control surface and the fourth air control surface;
is the deflection angle of the first air control surface and the second air control surface,
the deflection angles of the third air control surface and the fourth air control surface,
in order to be the density of the air,
for the speed of the propeller air wash acting on the control surface,
、
for the corresponding dimensionless aerodynamic coefficients,
the length of the force arm from the third air control surface and the fourth air control surface to the axis of the unmanned aerial vehicle,
the length of the force arm from the first air control surface and the second air control surface to the axis of the unmanned aerial vehicle,
the area of a control surface in the washing flow of the propeller;
when the PID roll controller obtains the reference roll angle from the IMU, calculating the reference deflection angle of the second pair of air control surfaces according to the formulas (13), (14), (23) - (25) in the same way; the PWM signal resolving module calculates a PWM value corresponding to the reference deflection angle of the control surface, then outputs a PWM signal to a steering engine of a second pair of air control surfaces to complete deflection of the second pair of air control surfaces, and the unmanned aerial vehicle generates roll angle deflection under the action of the control surfaces to realize steering motion;
when the PID yaw controller obtains the reference yaw angle from the IMU, the reference torque difference of the coaxial counter-rotating motor is calculated according to the formulas (13), (14), (23) and (25) in the same way, the reference rotating speed difference of the coaxial counter-rotating motor is further obtained according to the relation between the torque and the rotating speed of the motor, the PWM signal resolving module calculates the PWM value corresponding to the reference rotating speed difference, then the PWM signal is output to the coaxial counter-rotating motor, the rotation of the screw blades at different rotating speeds is completed, and the unmanned aerial vehicle realizes yaw motion under the action of the torque difference generated by the forward and reverse blades.
Has the advantages that: compared with the prior art, the invention has the following remarkable advantages: the invention adopts a coaxial double-oar structure, and the double-oar structure can overcome most of torque by the oar blades, so that the control surface for changing the posture of the unmanned aerial vehicle can be designed to be very small, the volume of the unmanned aerial vehicle is greatly reduced, the portability and the maneuverability are improved, and the requirement of high maneuvering operation can be met. The unmanned aerial vehicle shell is cylindrical, and can play a role in rectification well, so that a large amount of air media are directly pushed to a control surface by propeller blades, and a strong control effect is generated. The lever principle is ingeniously utilized by the two pairs of air control surfaces, the length of a force arm is increased, and the unmanned aerial vehicle can stably control the front, back, left and right movements through the rapid deflection of the air control surfaces under the condition of limited control surface area. On the other hand, the structure that the lift force acts on the upper part of the gravity center and the control force of the control surface acts on the lower part of the gravity center can obviously improve the stability of the aircraft, so that the attitude control is more flexible and effective.
Drawings
Fig. 1 is a schematic view of the overall structure of a coaxial twin-paddle unmanned aerial vehicle according to an embodiment of the invention.
Fig. 2 is a schematic view of the installation of the bottom control surface of the coaxial twin-oar unmanned aerial vehicle according to the embodiment of the invention.
Fig. 3 is a control surface layout diagram of the embodiment of the invention.
FIG. 4 is a 3D model design diagram according to an embodiment of the present invention.
Fig. 5 is a schematic diagram of a machine body fixed connection coordinate system in the embodiment of the invention.
FIG. 6 is an inertial coordinate system of the machine body
Conversion to a machine body fixed connection coordinate system
Schematic representation.
Fig. 7 is a schematic diagram of forward motion control of a coaxial twin-screw drone according to an embodiment of the invention;
wherein, (a) is a pitch angle control principle diagram, and (b) is a pitch angle control surface deflection top view.
FIG. 8 illustrates the control principle of the right motion of the coaxial twin-screw unmanned aerial vehicle according to the embodiment of the present invention;
wherein, (a) is a roll angle control principle diagram, and (b) is a roll angle control surface deflection plan view.
FIG. 9 illustrates the principle of the directional right turn control of a coaxial twin-screw unmanned aerial vehicle according to an embodiment of the invention;
wherein, (a) is a yaw angle control principle diagram, and (b) is a rotating top view of a yaw angle control motor.
Detailed Description
The technical solution of the present invention will be further described with reference to the following embodiments and the accompanying drawings.
As shown in fig. 1 and 2, the portable micro coaxial twin-screw unmanned aerial vehicle disclosed in the embodiments of the present invention includes an unmanned aerial vehicle housing 9, coaxial twin-screws 1 and 2, a transmission rod 8, and the like, wherein the unmanned aerial vehicle housing 9 is cylindrical, the transmission rod 8 and the coaxial twin-screws 1 and 2 are disposed at the top of the housing, and a coaxial counter-rotating motor 3, a battery 7, an autopilot system 5, and four steering engines 14 are installed inside the unmanned aerial vehicle housing. Double screw 1, 2 demountable installation are in the unmanned aerial vehicle top, are connected with 3 output shafts of coaxial counter-rotating motor through transfer line 8, go up screw 1 and fix on the output shaft of motor down, and lower screw 2 is fixed on the output shaft of last motor. Four air control surfaces which are distributed in a cross shape are installed at the bottom end of the unmanned aerial vehicle shell 9 and are respectively controlled by corresponding steering engines 14, a first pair of air control surfaces 11 (comprising a first air control surface and a second air control surface) are symmetrically installed on two opposite sides of the outer wall of the unmanned aerial vehicle shell 9, and a second pair of air control surfaces 12 (comprising a third air control surface and a fourth air control surface) are symmetrically installed on two other sides of the outer wall of the unmanned aerial vehicle shell 9. For convenient fixing, unmanned aerial vehicle shell internally mounted has first fixed plate 4, second fixed plate 6, third fixed plate 15 motor 3 to rely on first fixed plate 4, and autopilot system 5 and battery 7 are arranged in the upper and lower face of second fixed plate 6 respectively, and accessible magic is pasted the adhesion and is bandage fixed. The first fixing plate 4, the second fixing plate 6 and the third fixing plate 15 are provided with additional ventilation holes for heat dissipation and the like besides corresponding threading holes. The unmanned aerial vehicle cabin body 10 is reasonable in space design, so that modules such as an electric controller, a data transmitter and a remote controller receiver are arranged in the unmanned aerial vehicle cabin body uniformly and reasonably, and the gravity center of the unmanned aerial vehicle is arranged on a symmetrical axis of a fuselage.
The automatic pilot system 5 comprises a flight control module with an IMU (inertial measurement unit) and a data transmission module, can realize self attitude control of the unmanned aerial vehicle, and the attitude control comprises course attitude control, longitudinal attitude control and transverse attitude control. Based on the structural design of the unmanned aerial vehicle, the unmanned aerial vehicle can generate torque difference by adjusting the rotation speed difference of double propellers, so that course deflection motion is realized, the unmanned aerial vehicle can generate pitch angle deflection under the action of control surfaces by adjusting the deflection angles of the first pair of air control surfaces, so that front and back motion is realized, and the unmanned aerial vehicle can generate roll angle deflection under the action of the control surfaces by adjusting the deflection angles of the second pair of air control surfaces, so that steering motion is realized.
The rotating directions of the propellers 1 and 2 are opposite, and the upper propeller 1 is fixed on the lower motor output shaft of the coaxial counter-rotating motor 3 and rotates anticlockwise; the lower propeller 3 is fixed on the upper motor output shaft of the coaxial counter-rotating motor 3, rotates clockwise, and the output shaft of the coaxial counter-rotating motor 3 forms a transmission rod 8. The lift that two screw provided all points to the top along the fuselage symmetry axis, but the direction of the moment of torsion that provides along fuselage symmetry axis rotation is opposite, so when the moment of torsion size that two paddles formed is the same, just can overcome the spin of unmanned aerial vehicle organism. When the torque formed by the two blades is different, the heading deflection action of the unmanned aerial vehicle is realized just by using the torque difference. When the clockwise torque acting on the machine body is larger than the anticlockwise torque, the machine body yaw rotates clockwise; otherwise, when the anticlockwise torque is larger than the clockwise torque, the machine body rotates in an anticlockwise yawing mode
The four control surfaces are respectively connected with the four steering engines 14 and are distributed at the bottom of the unmanned aerial vehicle shell 9 in a cross manner, and as shown in fig. 3, the shape of the control surfaces is designed in the embodiment. The hollow cylinder design in the middle of the control surface not only facilitates the installation and the disassembly, but also enables the lower washing air flow of the propeller to better act on the control surface through the aerodynamic principle, thereby improving the control effect. The two pairs of air control surfaces 11 and 12 utilize the lever principle, the length of a force arm is increased, and the unmanned aerial vehicle can stably control the front-back and left-right movement through the quick deflection of the air control surfaces under the condition of limited control surface area. Meanwhile, the structure that the lift force acts on the upper part of the gravity center and the control force of the control surface acts on the lower part of the gravity center can obviously improve the stability of the aircraft, so that the attitude control is more flexible and effective.
The unmanned aerial vehicle shell is cylindrical, and can play the rectification effect well. Meanwhile, the circular protective covers 16 are designed and installed on the periphery of the four control surfaces, so that the control surfaces can be protected, and the effect of utilizing the washing flow of the propeller at the maximum efficiency can be achieved, so that a large amount of air media are directly pushed to the control surfaces by propeller blades, and a strong control effect is generated. The model of the final design is shown in fig. 4.
The automatic pilot system 5 can sense the flight attitude of the unmanned aerial vehicle, and can complete the quick response of the unmanned aerial vehicle to the reference attitude angle by adjusting the deflection direction of the bottom air control surfaces 11 and 12; the deflection directions of the air control surfaces 11 and 12 at the bottom of the unmanned aerial vehicle can be adjusted when the unmanned aerial vehicle is unstable, so that disturbance counteracting force is provided for the unmanned aerial vehicle; the course angle deflection of the unmanned aerial vehicle at a given speed can be realized by adjusting the rotating speed difference between the upper blade 1 and the lower blade 2. The control method is realized by PID adjustment, and before a specific implementation process is introduced, a mathematical model of the coaxial double-oar unmanned aerial vehicle is described first.
1. Definition of coordinate system
Before modeling the aircraft, a reference system serving as a reference standard is given, a ground inertial coordinate system is used as a reference standard, and an aircraft body inertial coordinate system and an aircraft body fixed connection coordinate system of the aircraft are required to be matched with the ground inertial coordinate system.
Ground inertia coordinate system
The origin point of the unmanned plane is fixedly connected with the takeoff position of the unmanned plane under the coordinate systemXUnit vector on axis
The direction is to the north of the sun,Yunit vector on axis
Is pointing toIn the east of the year or month,Zunit vector on axis
Pointing to the Earth's center is known as the North east Earth's reference frame.
Inertial coordinate system of machine body
(if not stated otherwise, the inertial coordinate system refers to the inertial coordinate system of the airframe), the origin of coordinates is located at the center of mass of the unmanned aerial vehicle, each coordinate axis of the inertial system of the airframe is kept horizontal with the inertial system of the ground, that is, under the inertial coordinate system of the airframe,Xunit vector on axis
The direction is to the north of the sun,Yunit vector on axis
Is directed to the right east,Zunit vector on axis
Pointing to the earth's center.
Coordinate system of machine body fixed connection
(hereinafter, the coordinate system of the unmanned aerial vehicle refers to a coordinate system fixedly connected with the unmanned aerial vehicle if not stated otherwise), and the origin of the coordinate is located at the center of mass of the unmanned aerial vehicle under the coordinate systemXUnit vector on axis
Is vertical to the longitudinal axis of the machine body and points to the front,Yunit vector on axis
Is perpendicular to the longitudinal axis of the unmanned aerial vehicle and points to the right side of the unmanned aerial vehicle,Zunit vector on axis
Pointing downwards along the longitudinal axis of the body, as shown in the figure5, respectively.
After the reference frame of the aircraft is determined, the attitude of the aircraft may be determined based on the transitions between the respective reference frames. There are generally two ways to represent the attitude of an aircraft: euler angles and quaternions. The Euler angle is the most intuitive and direct method for representing the posture of the aircraft body and corresponds to the actual posture angle of the aircraft; the quaternion has the capability of global attitude description, but has no clear physical significance, and has certain difficulty when being used for designing the controller, so that the Euler angle is selected as the attitude description method in the embodiment of the invention.
In an inertial frame fixedly associated with the aircraft, of a frameXThe axis is directed to the north direction,Ythe axis is directed to the east,Zthe shaft is directed towards the ground. The most basic method for representing the relationship between the inertial coordinate system and the body coordinate system is to use a rotation matrix
Rotation matrix
Is a 3x3 matrix, multiplied by which the vector rotated to the representation in the current coordinate system is obtained:
euler angles are the most common method for representing the attitude of an aircraft, and represent the attitude of the aircraft as a sequence of three consecutive rotations, such as the 3-2-1 or ZYX euler angle sequence commonly used for fixed-wing aircraft,
in order to be the pitch angle,
in order to form a transverse rolling angle,
for yaw angle, as shown in fig. 6:
(1) inertial frame
Wound around
Rotate
To
In a coordinate system;
（2）
coordinate system wound around
Rotate
To
In a coordinate system;
（3）
coordinate system wound around
Rotate
To the body coordinate system
；
This process is represented by a rotation matrix as:
wherein the content of the first and second substances,
is to represent the conversion process from an inertial system to a body system, the subscript of R represents the coordinate system being rotated, the superscript of R represents the coordinate system to be rotated into, and the three rotation matrices can be combined to form a combined inertial system
To
The rotation matrix of (a):
2. aircraft kinetic equation
In an inertial coordinate system, the mass center motion equation of the aircraft under the action of the resultant external force is as follows:
setting force
Can be decomposed into
Then the centroid kinetic equation is expressed as
Under the body coordinate system, the rigid body rotation dynamic equation of the aircraft is given by a Newton Euler equation:
in the formula (I), the compound is shown in the specification,
is the moment of momentum of the unmanned aerial vehicle,
the aircraft is subjected to external torque.
Moment of momentum
Under the coordinate system of the machine body
WhereinJIs the rotational inertia of the unmanned aerial vehicle,
。
therefore, it is
Then under the body coordinate system, the rotational dynamics equation can be written as follows:
setting torque
Under the machine system, the three components are
Then there is
3. Kinematic equation of aircraft
The kinematic equations of the aircraft do not involve forces and moments, and the aircraft is regarded as a whole in relation to the spatial position in which it is located. Considering the rotation motion of the aircraft around the mass center, the relationship between the attitude angular rate of the aircraft and 3 angular velocity components under the coordinate axis of the body is
When the speed of the aircraft in each axis direction under the coordinate axis of the airframe is converted into the speed under the inertial coordinate system of the ground, the three-dimensional space position of the aircraft can be expressed by the following formula
4. Unmanned aerial vehicle resultant force and resultant moment analysis
Analysis is carried out under a machine body coordinate system, force and moment borne by the coaxial double-oar unmanned aerial vehicle mainly come from three aspects, namely propeller tension, control surface control force and gravity, and a formula of resultant force and resultant moment is as follows:
in the formula (I), the compound is shown in the specification,
in order to generate the pulling force for the propeller,
sequentially represents an upper propeller and a lower propeller;
is the aerodynamic force on the control surface,
sequentially showing four control surfaces clockwise;
for the torque (N · m) generated by the propeller,
sequentially represents an upper propeller and a lower propeller;
is the aerodynamic moment on the control surface,
showing four control surfaces clockwise in turn.
Propeller tension
The tensile force vector that coaxial two oar unmanned aerial vehicle's upper and lower screw produced is as follows:
the pull force provided by the propeller is related to the motor speed and is a function of the square of the motor speed
In the formula (I), the compound is shown in the specification,
in order to be the coefficient of tension,
is the corresponding motor speed.
Aerodynamic force of control surface
Because unmanned aerial vehicle flying speed is lower, the influence of airspeed to the control plane can be ignored, only considers the influence of screw washing flow to the control plane. The effect of the propeller wash on the control surfaces is mainly the forces along the X-axis of the fuselage and the forces along the Y-axis of the fuselage,
the force along the X axis of the fuselage is provided by the first and second air control surfaces:
the force along the Y axis of the fuselage is provided by the third and fourth air control surfaces:
in the formula (I), the compound is shown in the specification,
in order to be the density of the air,
for the speed of the propeller air wash acting on the control surface,
for the corresponding dimensionless aerodynamic derivative of the control surface,
is the deflection angle of the first air control surface and the second air control surface,
the deflection angles of the third air control surface and the fourth air control surface,
is the control surface area within the propeller wash stream.
The control force vector generated by the four control surfaces is
Gravity force
In the formula (I), the compound is shown in the specification,mthe mass of the unmanned aerial vehicle is the mass of the unmanned aerial vehicle,gis the acceleration of gravity.
Torque of
The torque generated by the upper and lower propellers of a coaxial double-propeller motor can be expressed as
In the formula (I), the compound is shown in the specification,
as a function of the square of the motor speed,
，
is the relevant tension coefficient.
Because unmanned aerial vehicle flying speed is lower, the influence of airspeed to the control plane can be ignored, only considers the influence of screw washing flow to the control plane. The aerodynamic moment generated by the propeller wake pair control surface in a machine body coordinate system around the X axis and the Y axis is respectively:
in the formula (I), the compound is shown in the specification,
and
for the corresponding dimensionless aerodynamic coefficients,
the length of the force arm from the third air control surface and the fourth air control surface to the axis of the unmanned aerial vehicle,
the length of the force arm from the first air control surface and the second air control surface to the axis of the unmanned aerial vehicle.
It is possible to obtain,
so far, the mathematical model of the unmanned aerial vehicle is obtained.
Based on the established mathematical model, the portable micro coaxial double-oar unmanned aerial vehicle provided by the embodiment of the invention can be subjected to structure optimization and control design. Specifically, acquire unmanned aerial vehicle body parameter, acquire the attitude information parameter including the combination navigation, carry out the fitting through wind tunnel test and acquire the fitting relation of measuring wind speed wind direction and disturbance acceleration, obtain pneumatic model, can be used to verify whether reasonable, the flight of unmanned aerial vehicle structure designed is stable, helps the performance such as load and anti-wind of analysis unmanned aerial vehicle.
The design of the unmanned aerial vehicle flight attitude controller is carried out on the basis of a mathematical model, and the unmanned aerial vehicle flight attitude controller mainly comprises a PID pitching controller, a PID rolling controller and a PID yaw controller. When the output signal (real flight track) of the unmanned aerial vehicle has an error with (reference input) a preset flight track, an error signal is generated, the signal is processed by the controller to become the input signal of the execution element (namely, a control surface and a propeller), the execution element is controlled to adjust the control object (the attitude and the speed of the unmanned aerial vehicle), in the process, the unmanned aerial vehicle can also receive external disturbance signals (such as gust and the like), the actual output signal is converted by the measuring element (a gyroscope, an accelerometer and the like) and then is compared with the reference signal to form closed-loop control, and therefore the flight control of the unmanned aerial vehicle is achieved.
For fast, stable and reliable control, a controller of the flight attitude of the unmanned aerial vehicle adopts a PID control strategy, taking attitude control as an example, an error signal of an attitude angle is not directly output to an actuating mechanism, but is converted into an expected attitude angular velocity signal, the expected attitude angular velocity signal is compared with a real attitude angular velocity signal, an input signal of the actuating mechanism is calculated, and the action of the actuating mechanism is controlled. And inputting the calculated control signal to the steering engine to complete the deflection of the air control surface, generating the pitch angle deflection (or the roll angle deflection) by the unmanned aerial vehicle under the action of the control surface, and inputting the calculated control signal to the coaxial counter-rotating motor to complete the yaw of the unmanned aerial vehicle. Thereby realizing forward movement, steering movement and corresponding posture adjustment action.
Fig. 7 is a schematic diagram of forward motion control of a coaxial twin-paddle unmanned aerial vehicle. When the forward leaning reference pitch angle of the drone is given, the control flow is as shown in (a) of fig. 7. Firstly, the PID pitch controller calculates the reference deflection angle of a first pair of air control surfaces according to formulas (13), (14), (23) - (25), secondly, the PWM signal resolving module calculates the PWM value corresponding to the reference deflection angle of the control surfaces, and then the PWM signal is input to the steering engine of the first pair of air control surfaces to complete the deflection of the first pair of air control surfaces, as shown in (b) of fig. 7, at the moment, the unmanned aerial vehicle generates pitch angle deflection under the action of the control surfaces to realize fore-and-aft motion.
Fig. 8 is a schematic diagram of the control of the right motion of the coaxial twin-paddle unmanned aerial vehicle. When the unmanned aerial vehicle right-leaning reference roll angle is given, the control flow is as shown in (a) of fig. 8. Firstly, the PID roll controller calculates the reference deflection angle of the second pair of air control surfaces according to the formulas (13), (14), (23) - (25), secondly, the PWM signal calculation module calculates the PWM value corresponding to the reference deflection angle of the control surfaces, and then the PWM signal is input to the steering engine of the second pair of air control surfaces to complete the deflection of the second pair of air control surfaces, as shown in (b) of figure 8, at the moment, the unmanned aerial vehicle generates roll angle deflection under the action of the control surfaces to realize steering motion.
Fig. 9 is a schematic diagram of the heading right-turn control of the coaxial twin-paddle unmanned aerial vehicle. When the unmanned aerial vehicle is given a right-direction reference yaw angle, the control flow is as shown in (a) of fig. 9. Firstly, a PID yaw controller calculates the reference torque difference of the coaxial counter-rotating motor according to formulas (13), (14), (23) - (25), further calculates the reference rotating speed difference of the motor according to the relation between the torque and the rotating speed of the motor, then a PWM signal resolving module calculates a PWM value corresponding to the reference rotating speed difference, and then outputs a PWM signal to the coaxial counter-rotating motor to finish the rotation of the propeller blades at different rotating speeds, as shown in (b) of figure 9, at the moment, the unmanned aerial vehicle realizes the right-direction yaw motion under the action of the torque difference generated by the forward and reverse propeller blades.
The invention adopts a coaxial double-paddle structure, the double-paddle structure can easily overcome self torque by positive and negative paddles, and the control surface design of the cylindrical tail part controls the attitude change to realize various actions of the unmanned aerial vehicle in the air. Because lift torque control structure and attitude control structure distribute respectively in cylindric aircraft's upper end and lower extreme, ingenious utilized lever principle, increased arm of force length for control has very strong stability and robustness, and attitude control's control surface design can allow very little area just can reach the requirement that unmanned aerial vehicle gesture changed simultaneously, has reduced unmanned aerial vehicle's volume greatly, has improved portability and mobility, can satisfy the demand of high maneuver battle. Experiments prove that the portable micro coaxial double-propeller unmanned aerial vehicle provided by the invention has the advantages of reasonable structure and control design, strong portability and maneuverability and good application prospect.
The above description is only an embodiment of the present invention, and not intended to limit the scope of the present invention, and all equivalent structural changes made by using the contents of the present specification and the drawings can be directly or indirectly applied to other related technical fields, and all such changes are encompassed in the scope of the present invention.
Claims (9)
1. A portable microminiature coaxial double-propeller unmanned aerial vehicle is characterized by comprising a cylindrical unmanned aerial vehicle shell (9), wherein the top of the shell (9) is provided with a transmission rod (8) and coaxial double propellers, and a coaxial counter-rotating motor (3), a battery (7), an autopilot system (5) and four steering engines (14) are arranged in the shell; the double propellers are arranged at the top end of the unmanned aerial vehicle and connected with an output shaft of the counter-rotating shaft motor (3) through a transmission rod (8); four air control surfaces which are distributed in a cross shape are arranged on the periphery of the bottom end of the shell (9) and are respectively controlled by corresponding steering engines (14), a first pair of air control surfaces (11) comprises a first air control surface and a second air control surface and are symmetrically arranged on two opposite sides of the outer wall of the unmanned aerial vehicle shell (9), and a second pair of air control surfaces (12) comprises a third air control surface and a fourth air control surface and are symmetrically arranged on the other two sides of the outer wall of the unmanned aerial vehicle shell (9); the automatic pilot system (5) is used for realizing attitude control of the unmanned aerial vehicle, the unmanned aerial vehicle generates torque difference by adjusting double propeller rotation speed difference so as to realize course deflection motion, the unmanned aerial vehicle generates pitch angle deflection under the action of a first pair of air control surfaces (11) by adjusting deflection angles of the first pair of air control surfaces so as to realize front and back motion, and the unmanned aerial vehicle generates roll angle deflection under the action of the control surfaces by adjusting deflection angles of a second pair of air control surfaces (12) so as to realize steering motion;
under a body coordinate system, resultant force borne by the unmanned aerial vehicle comprises propeller pulling force, control surface control force and gravity; the tension vectors generated by the upper propeller and the lower propeller are as follows:
wherein
In order to generate the pulling force for the propeller,
sequentially representing an upper propeller and a lower propeller, wherein the pulling force provided by the propellers is a function of the square of the rotating speed of the motor; the control forces generated by the four control surfaces are as follows:
wherein
，
，
In order to be the density of the air,
for the speed of the propeller air wash acting on the control surface,
is a dimensionless aerodynamic derivative of the control surface,
is the deflection angle of the first air control surface and the second air control surface,
the deflection angles of the third air control surface and the fourth air control surface,
the area of a control surface in the washing flow of the propeller;
the resultant moment borne by the unmanned aerial vehicle comprises torque generated by an upper propeller and a lower propeller and aerodynamic moment generated by the wake flow of the propellers on a control surface; the torque generated by the upper propeller and the lower propeller is as follows:
wherein
The torque generated by the propellers is a function of the square of the rotating speed of the motor; the aerodynamic moment generated by the propeller wake flow on the control surface is as follows:
wherein
，
，
And
for the corresponding dimensionless aerodynamic coefficients,
the length of the force arm from the third air control surface and the fourth air control surface to the axis of the unmanned aerial vehicle,
the length of the force arm from the first air control surface and the second air control surface to the axis of the unmanned aerial vehicle.
2. The portable microminiature coaxial twin-screw unmanned aerial vehicle of claim 1, wherein the directions of rotation of the coaxial twin-screw are opposite, and the upper screw (1) is fixed on the lower motor output shaft of the coaxial counter-rotating motor (3) and rotates counterclockwise; the lower propeller (2) is fixed on an upper motor output shaft of the coaxial counter-rotating motor (3) and rotates clockwise; the output shaft of the coaxial counter-rotating motor (3) forms a transmission rod (8).
3. The portable microminiature coaxial twin-screw unmanned aerial vehicle of claim 1, wherein the lifting forces provided by the coaxial twin-screws are all directed upwards along the symmetry axis of the vehicle body, the directions of the torques provided to rotate along the symmetry axis of the vehicle body are opposite, and when the torques formed by the two blades are the same, the self-rotation of the unmanned aerial vehicle body can be overcome; when the torque formed by the two blades is different, the course deflection action of the unmanned aerial vehicle is realized by utilizing the torque difference; when the clockwise torque acting on the machine body is larger than the anticlockwise torque, the machine body yaw rotates clockwise; when the anticlockwise torque is larger than the clockwise torque, the machine body rotates anticlockwise in a yawing mode.
4. The portable microminiature coaxial double-oar unmanned aerial vehicle of claim 1, wherein the unmanned aerial vehicle housing (9) is internally provided with a first fixing plate (4), a second fixing plate (6) and a third fixing plate (15) for fixing the motor (3), the autopilot system (5) and the battery (7), and the steering engine (14), respectively; the first fixing plate (4), the second fixing plate (6) and the third fixing plate (15) are provided with threading holes and ventilation holes.
5. The portable micro-miniature coaxial twin-paddle unmanned aerial vehicle of claim 1, wherein the middle of each of the four air control surfaces is of hollow cylinder design.
6. The portable micro miniature coaxial twin-screw unmanned aerial vehicle of claim 1, wherein the lifting force provided by the coaxial twin-screw acts above the center of gravity of the unmanned aerial vehicle and the control force provided by the air control surface acts below the center of gravity.
7. The portable microminiature coaxial twin-paddle unmanned aerial vehicle of claim 1, wherein the four air rudder faces are peripherally fitted with circular protective covers (16).
8. The portable microminiature coaxial twin-oar unmanned aerial vehicle of claim 1, wherein the modules in the unmanned aerial vehicle cabin (10) are arranged uniformly and reasonably, so that the unmanned aerial vehicle center of gravity is on the symmetry axis of the vehicle body.
9. The method for controlling a portable microminiature coaxial twin-paddle unmanned aerial vehicle as claimed in any one of claims 1-8, comprising the steps of:
when the PID pitch controller obtains a reference pitch angle from the IMU, calculating a reference deflection angle of a first pair of air control surfaces (11) according to the following formula; the PWM signal resolving module calculates a PWM value corresponding to the reference deflection angle of the control surface, then outputs PWM signals to the steering engine of the first pair of air control surfaces (11) to complete deflection of the first pair of air control surfaces (11), and the unmanned aerial vehicle generates pitch angle deflection under the action of the control surfaces to realize fore-and-aft motion;
wherein
Is resultant moment
Three components in the coordinate system of the machine body,
for the three components of the angular velocity vector in the body coordinate system, the points on the variable represent the derivatives,
in order to be the pitch angle,
in order to form a transverse rolling angle,
in order to determine the yaw angle,
is the rotational inertia of the unmanned plane
The respective components of (a); under the coordinate system of the unmanned aerial vehicle, the origin of coordinates is located at the center of mass of the unmanned aerial vehicle,Xthe axis is vertical to the longitudinal axis of the unmanned aerial vehicle and points to the front of the unmanned aerial vehicle,Ythe shaft is perpendicular to the longitudinal axis of the unmanned aerial vehicle and points to the right side of the unmanned aerial vehicle,Zthe shaft points downwards along the longitudinal axis of the machine body;
when the PID roll controller obtains the reference roll angle from the IMU, calculating the reference deflection angle of the second pair of air control surfaces (12) according to the formulas (13), (14), (23) - (25) in the same way; the PWM signal resolving module calculates a PWM value corresponding to the reference deflection angle of the control surface, then outputs a PWM signal to a steering engine of a second pair of air control surfaces (12) to complete deflection of the second pair of air control surfaces (12), and the unmanned aerial vehicle generates roll angle deflection under the action of the control surfaces to realize steering motion;
when the PID yaw controller obtains the reference yaw angle from the IMU, the reference torque difference of the coaxial counter-rotating motor (3) is calculated according to the formulas (13), (14), (23) and (25) in the same way, the reference speed difference of the coaxial counter-rotating motor (3) is obtained according to the relation between the torque and the motor speed, the PWM signal resolving module calculates the PWM value corresponding to the reference speed difference, then the PWM signal is output to the coaxial counter-rotating motor (3), the rotation of the screw blades at different rotating speeds is completed, and the unmanned aerial vehicle realizes yaw movement under the action of the torque difference generated by the forward and reverse blades.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110754731.5A CN113200145B (en) | 2021-07-05 | 2021-07-05 | Portable micro coaxial double-propeller unmanned aerial vehicle and control method thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110754731.5A CN113200145B (en) | 2021-07-05 | 2021-07-05 | Portable micro coaxial double-propeller unmanned aerial vehicle and control method thereof |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN113200145A CN113200145A (en) | 2021-08-03 |
| CN113200145B true CN113200145B (en) | 2021-10-01 |
Family
ID=77022693
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202110754731.5A Active CN113200145B (en) | 2021-07-05 | 2021-07-05 | Portable micro coaxial double-propeller unmanned aerial vehicle and control method thereof |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN113200145B (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN117104546B (en) * | 2023-10-16 | 2024-01-05 | 中国空气动力研究与发展中心计算空气动力研究所 | Multi-duct unmanned aerial vehicle and control method |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101244762A (en) * | 2008-03-21 | 2008-08-20 | 周公平 | Power-driven system of aerial vehicle |
| CN105539830A (en) * | 2015-12-31 | 2016-05-04 | 歌尔科技有限公司 | Air vehicle |
| CN107097949A (en) * | 2017-04-25 | 2017-08-29 | 河南三和航空工业有限公司 | A kind of VTOL fixed-wing unmanned plane |
| CN110155316A (en) * | 2019-06-09 | 2019-08-23 | 西北工业大学 | A kind of coaxial twin screw vertically taking off and landing flyer of Moving mass control and its control method |
| CN112678157A (en) * | 2020-12-31 | 2021-04-20 | 南京傲宁数据科技有限责任公司 | Portable microminiature single rotor unmanned aerial vehicle |
-
2021
- 2021-07-05 CN CN202110754731.5A patent/CN113200145B/en active Active
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101244762A (en) * | 2008-03-21 | 2008-08-20 | 周公平 | Power-driven system of aerial vehicle |
| CN105539830A (en) * | 2015-12-31 | 2016-05-04 | 歌尔科技有限公司 | Air vehicle |
| CN107097949A (en) * | 2017-04-25 | 2017-08-29 | 河南三和航空工业有限公司 | A kind of VTOL fixed-wing unmanned plane |
| CN110155316A (en) * | 2019-06-09 | 2019-08-23 | 西北工业大学 | A kind of coaxial twin screw vertically taking off and landing flyer of Moving mass control and its control method |
| CN112678157A (en) * | 2020-12-31 | 2021-04-20 | 南京傲宁数据科技有限责任公司 | Portable microminiature single rotor unmanned aerial vehicle |
Also Published As
| Publication number | Publication date |
|---|---|
| CN113200145A (en) | 2021-08-03 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN107368091B (en) | A kind of stabilized flight control method of more rotor unmanned aircrafts based on finite time neurodynamics | |
| Bapst et al. | Design and implementation of an unmanned tail-sitter | |
| JP2023082107A (en) | Vertical takeoff and landing (vtol) air vehicle | |
| US20120286102A1 (en) | Remotely controlled vtol aircraft, control system for control of tailless aircraft, and system using same | |
| Rodić et al. | Modeling and simulation of quad-rotor dynamics and spatial navigation | |
| JP2022552431A (en) | Separate lift-thrust VTOL aircraft with articulated rotors | |
| CN106114853B (en) | A kind of push-button aircraft | |
| EP2323905A2 (en) | Rotary wing vehicle | |
| CN106394895B (en) | A kind of polymorphic unmanned plane and its flight control method | |
| JP2010254264A (en) | Unmanned aircraft landing and departing perpendicularly by tilt wing mechanism | |
| CN109606674A (en) | Tail sitting posture vertical take-off and landing drone and its control system and control method | |
| Wenfu et al. | Flight control of a large-scale flapping-wing flying robotic bird: System development and flight experiment | |
| JP2022509697A (en) | Aircraft with separate degrees of freedom | |
| GB2553604B (en) | Aerodynamically fully actuated drone (Sauceron) and drone chassis aerodynamic supporting trusses (Lings) | |
| CN110254703B (en) | Tilting double-rotor wing automatic hovering T-shaped unmanned aerial vehicle system | |
| CN112034868A (en) | Yaw control method and mechanism of bionic micro flapping wing aircraft | |
| CN113200145B (en) | Portable micro coaxial double-propeller unmanned aerial vehicle and control method thereof | |
| CN114740762A (en) | Power parafoil semi-physical simulation system based on active-disturbance-rejection decoupling control strategy | |
| CN116643578B (en) | Multimode unified control method for microminiature tailstock unmanned aerial vehicle | |
| Kita et al. | Hovering control of a tail-sitter VTOL aerial robot | |
| CN108427432B (en) | Non-planar three-rotor aircraft and control method | |
| Wang et al. | Design, modelling and hovering control of a tail-sitter with single thrust-vectored propeller | |
| Khoo et al. | Robust control of novel thrust vectored 3D printed multicopter | |
| Servais et al. | Trajectory tracking of trirotor UAV with pendulum load | |
| WO2019241617A2 (en) | Systems and methods for controlling a vehicle |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |